Petroleum contamination poses a major threat to Antarctic and subantarctic ecosystems because diesel and lubricants are persistent and, at poorly defined concentrations, are toxic in marine environments. This project will asses how quickly important components in these products are ... naturally depleted using a model field experiment. We will identify and quantify the non-degrading portions of the fuels, and assess the longevity and rate of removal of these. We will relate the chemical analysis data with biological data on organisms in the sea-bottom sediments, in order to assess which components of the fuels do most harm to the organisms.

Project objectives: The overall objective is to better understand the long-term environmental impact of spilled petroleum products in Antarctic marine systems. Decades of Antarctic exploration have left a significant legacy of petroleum pollution on-land and in nearshore marine environments, particularly around human stations. The natural attenuation of spilled diesel and lubricants occurs slowly in cold climates, particularly once the pollutants have adsorbed onto marine sediments. Major programmes funded by the AAD have identified the location of spills, and the nature and fate of some of the pollutants. This project will address some of the significant uncertainties which still exist regarding the natural depletion and ecotoxicological impact of spilled diesel and lubricants in the marine environment. A new PhD student at Macquarie University will carry-out much of this work, in collaboration with the CI and investigators. The specific objectives are: 1. To develop a quantitative method using cutting edge two-dimensional gas chromatography-mass spectrometry (GCxGC-TOFMS) to identify the components of spilled diesel and lubricants, especially the complex mixtures of recalcitrant residues and the secondary products of alteration. 2. To calculate the rates of removal of pollutants in the marine environment by comprehensive statistical treatment of the chemical data-set, and to assess the processes by which this removal occurs (e.g. aerobic/anaerobic biodegradation, water-washing, etc). 3. To assess the degradation rates and longevity of pollutant components against the biology of the disturbed communities of microbes and microfauna in the same experiments, so as to form a hypothesis of which components of the complex mixtures have the most important ecotoxicological response and environment impact. 4. Using the most important single isolated or related groups of components, to test the specific ecotoxicological impact of each in the marine environment using a short-term field experiment and laboratory toxicity tests.

Taken from the 2008-2009 Progress Report: Progress against objectives: 1. A GCxGC-FID was installed at Macquarie University. No TOFMS has been purchased yet, due to non-funding of ARC Lief grant application. No further progress made towards this objective. 2. We have a comprehensive dataset now of the rates of removal of hydrocarbon components of SAB from the SRE4 experiment. Detailed GC-MS has been carried out so as to track removal of components in much more detail than can be achieved by GC-FID alone. TPH data have been calculated. The data has been utilised in the draft of one paper by Shane Powell (Powell, Stark, Snape, Woolfenden, Bowman, Riddle; Effects of diesel and lubricant oils on Antarctic benthic microbial communities over five years) which has not been submitted yet, and in an early draft of a paper by PhD student Ellen Woolfenden (E. N. M. Woolfenden, G. Hince, S. Powell, S. Stark, J. Stark, I. Snape, S. George; Effects of diesel and lubricant oils on Antarctic benthic microbial communities over five years). 3. This has partly been done, and is being written up by the Powell et al. paper referred to above. Detailed analysis of which are the most toxic compounds of SAB awaits further work-up of the data. 4. The field season to carry out this test was postponed from 08/09 to 09/10.

Taken from the 2009-2010 Progress Report: Progress against objectives:

1. An ARC LIEF grant application was successful and a TOFMS will be purchased from the funds gained in mid 2010.

2. So far the 0-1cm of 10cm cores of marine sediment spiked with Biodegradable lubricant, used lubricant, clean lubricant and Special Antarctic Blend (SAB) diesel have been analysed by gas chromatography coupled to a flame ionisation detector (GC-FID). Analyses by GC-FID allowed the Total Petroleum Hydrocarbon (TPH) concentration at each sample time to be calculated from statistical analysis. Further analyses were performed on the SAB sediments extractions by GC-MS (mass spectrometry). The chromatograms of the extractions were compared with chromatograms of standard mixtures of compounds and a compound identification library and thus, peaks were identified. From this peak identification, degradation patterns of compounds and groups of compounds could be seen; naphthalenes degrade less readily with increasing methyl groups but still degrade more readily than n-alkanes. From the analyses of the 0-1cm sediment extractions the most recalcitrant compounds were (adamantanes and diamantanes) and the most water soluble compounds were (naphthalenes and alkylnaphthalenes) in SAB diesel. The data has been written up in a draft paper by PhD student Ellen Woolfenden (E. N. M. Woolfenden, G. Hince, S. Powell, S. Stark, J. Stark, I. Snape, S. George; Effects of diesel and lubricant oils on Antarctic benthic microbial communities over five years). This paper will be submitted by May 2010.

We also have started analysing the depth profiles for SAB in the SRE4 experiment. It is interesting to know as to whether any biodegradation patterns will be seen in the 1-10 cm depths of the sediment. Therefore the cores have been sectioned into 1 cm intervals and extracted at AAD. The extractions are awaiting analysis by GC-FID initially and GC-MS for further analysis.

3. This has partly been done, and is being written up by a Shane Powell et al. paper, that has not been published yet. Detailed analysis of which are the most toxic compounds of SAB awaits further work-up of the data.

4. The field season to carry out this test was carried out by Ellen Woolfenden in fieldseason 09/10. Samples have been collected and are stored at AAD. Marine sediment was collected and different portions were spiked with certain compounds from each of these groups as well as a selection of n-alkanes and SAB diesel as a comparison. These sediments have been extracted and are awaiting analysis by GC-MS to identify which of the compounds are depleted most readily within the experimental groups without the influence of other compounds present in SAB diesel. Ellen will be analysing them later in 2010.

The dataset provided by Ellen Woolfenden contain a number of excel spreadsheets, as well as a word document providing further information about the data.

Purpose:
To examine the degradation of hydrocarbons in marine sediments.

Quality
The values provided in temporal and spatial coverage are approximate only.

Taken from the 2008-2009 Progress Report: Variations to work plan or objectives: The field season was postponed from 08/09 to 09/10. No TOFMS has been purchased yet. Other GC-MS methods will be utilised to provide the detailed chemical data necessary for this project.

Laboratory ... activity/analysis: GC-FID work to give bulk characteristics of TPH (total petroleum hydrocarbons) carried out on complete SAB series of samples from SRE-4.

GC-MS work to give characterise individual components of SAB carried out on complete SAB series of samples from SRE-4. This analysis included n-alkanes, isoprenoids, branched alkanes, cyclic alkanes, alkylbenzenes and alkylnapthalenes.

Data analysed and prepared for preparation.

Next steps: 1. Depth series from SRE-4 SAB samples, to examine what happens away form the sediment-water interface: After initially looking at the surface 0-1cm of SAB spiked marine sediment from the 10cm sample cores, and finding some interesting results, we propose analyses on core samples from different depths of the 10cm core be undertaken. This study will allow us to ascertain if similar biodegradation trends are seen at greater depth in the sediment. We hypothesise that there will be a lesser decrease in overall TPH but that this decrease will be due to biodegradation and the effects of weathering will not be seen to such an extent. It will also be of interest to compare the biological data at depth to the chemical data which has not been previously done. Initially we propose to take 9 depth samples at 1cm intervals from the SAB spiked cores; 1 core at T1 (5 weeks), 1 core at T3 (64 weeks) and 2 at T5 (260 weeks) due to the large relative standard deviation in degradation between these samples. Extraction of these samples will be done by the same procedure as before; DCM + milli-q water, tumble over night then separate the next morning, and analysis by GC-FID/GC-MS will produce enough information to establish whether there is degradation occurring at depths over time. If the results from this investigation show degradation for these few samples then analysis will be done on the remaining samples for all depths. If the data does not prove of interest then another option would be to do a similar investigation with the other oil treatments, i.e. the biodegradable lubricant, clean and used lubricants. (May-July 2009)

2. Examine other lubricating oil series from SRE-4, in same way as undertaken for SAB. (August 2010 - March 2010)

3. State hypothesis relating chemical analytical data on the complex mixture of SAB diesel and lubricants to ecotoxicological outcomes, and in particular to identify the components, maybe present in trace amounts, that have most effect (August 2009)

4. Prepare for field season (09/10) by using the most important single isolated or related groups of components. Test the specific ecotoxicological impact of each in the marine environment using a short-term field experiment and laboratory toxicity tests.

Access Constraints
These data are publicly available for download from the provided URL. The download file contains excel spreadsheets plus a word document providing further details about the data.